Various techniques have been provided for connection of peripherals devices to personal computers, workstations and related host devices. Traditionally, a common approach was a cable connection from the peripheral device to a standard serial or parallel port provided in the host device. In addition, some techniques have been used for providing wireless communication between the peripheral device and the host device. Some such wireless techniques have involved infrared transmitters and receivers. Other wireless techniques have involved radio frequency (RF) communication links.
Such wireless peripheral devices using RF links typically include a loop antenna formed on or even in a printed circuit board contained within the peripheral device. For example, a wireless mouse may include a mouse printed circuit board having a loop antenna formed directly on its surface. When such a device is operated, for example, at 27 MHz, the loop antenna formed on the printed circuit board may be 30 millimeters×60 millimeters. A 27 MHz antenna with such dimensions provides a good signal from a peripheral device located in relative proximity to the host device, for example, when they are separated by less than 1-2 meters.
Such antennas will, however, include resistive losses. Even where attempts are made to match the impedance of the RF transmitter to the impedance of the antenna, there will always be resistive losses in series with the antenna connection. In fact, there will be losses in series with the antenna itself. Such resistive losses include the resistance of the metal trace forming the antenna and include the skin effect in which current is forced to flow in a thin layer of metal near the surface of the printed circuit board at high frequencies.
Some wireless peripheral devices have also operated at higher frequencies, such as 2.4 GHz. These higher frequency devices, however, have not had significant practical success as peripheral devices. In part, this is due to the increased power consumption of these higher frequency devices compared to the relatively lower frequency devices, such as 27 MHz devices. In addition, such devices are typically somewhat complex and thus expensive. These higher frequency devices in the gigahertz range typically require significant impedance control due to running radio frequency signals from one place to another on a circuit board. In addition, all leads typically must be shielded and kept as short as possible, and the dimensions of all signal traces much be controlled as tightly as possible, to prevent reflections or power loss. Such requirements typically can not be made for low cost and low power requirements of many applications.
For this and other reasons, a need exists for the present invention.